In vitro chemopreventive effects of plant polysaccharides (Aloe barbadensis Miller, Lentinus edodes, Ganoderma lucidum and Coriolus versicolor)

A plant polysaccharide, Aloe gel extract, was reported to have an inhibitor y effect on benzo[a]pyrene (B[a]P)-DNA adduct formation in vitro and in viv o, Hence, chemopreventive effects of plant polysaccharides [Aloe barbadensi s Miller (APS), Lentinus edodes (LPS), Ganoderma lucidum (GPS) and Coriolus versicolor (CPS)] were compared using lit vitro short-term screening metho ds associated with both initiation and promotion processes in carcinogenesi s. In B[a]P-DNA adduct formation, APS (180 mu g/ml) was the most effective in inhibition of B[a]P binding to DNA in mouse liver cells. Oxidative DNA d amage (by 8-hydroxydeoxyguanosine) was significantly decreased by APS (180 mu g/ml) and CPS (180 mu g/ml). In induction of glutathione S-transferase a ctivity, GPS was found to be the most effective among plant polysaccharides , In screening antitumor promoting effects, APS (180 mu g/ml) significantly inhibited phorbol myristic acetate (PMA)-induced ornithine decarboxylase a ctivity in Balb/3T3 cells. In addition, APS significantly inhibited PMA-ind uced tyrosine kinase activity in human leukemic cells. APS and CPS signific antly inhibited superoxide anion formation, These results suggest that some plant polysaccharides produced both anti-genotoxic and anti-tumor promotin g activities in in vitro models and, therefore, might be considered as pote ntial agents for cancer chemoprevention.